Phonographic apparatus



Dec. 13, 1949 H. E. Rays 2,491,215

PHONOGRAPHIC APPARATUS Y File May 29', 1944 l Znventor HENRY ERDYS l Gttomeg Patented Dec. 13, 1949 PHONOGRAPHIC APPARATUS Henry E. Roys, Indianapolis, lnd., assignor to Radio Corporation of America, a corporation of Delaware Application May Z9, 1944, Serial No. 537,915

3 Claims.

This invention relates to phonographic apparartus, and more particularly to a recording device for recording signals on a record blank.

In certain types of sound recording apparatus, it has been found advantageous to employ a socalled adv-ance ball (a) for supporting the Weight 'of the recording head and thus largely relieving the recording stylus of this burden, and (b) for controlling the depth of lpenetration of the recording stylus into the record, whereby to control the depth of the groove formed by the stylus in the blank. With certain types .of sound recording machines, particulraly those operating on dics record blanks, it is possi-ble to arrange the recorder head to :be driven in either one of two opposite directions across the record. Thus, in the case of discrecording machines of this type, the recording head may be arranged to move radially over the disc either from a point near the periphery thereof toward its center for outside-in recording, or from adjacent the center of the disc toward the periphery thereof for inside-out recording.

In lprior art recording machines employing an advance ball, the ball is mounted in a iixed location on the recorder head somewhat in advance of the recording stylus in the direction of movement of the recorder head across the record. Obviously, therefore, any given recorder head provided with such an advance ball will be suitable either for outside-in recording or for inside-out recording, but not for both because a iixed advance ball can be in advance of the recording stylus on only one side thereof. Considered from this aspect, then, it is apparent that a recording machine otherwise useful for either outside-in or inside-out recording becomes limited to recording in only one direction if an advance ball is to be used on the recording head thereof according to customary practice.

The primary object of my present invention, therefore, is to provide an improved two-way recording apparatus which will be free from the above mentioned limitation.

More particularly, it is an yobject of my present invention to provide, in a sound recording machine, an improved recording head which is provided with an advance ball and which can, nevertheless, be used for either inside-out or outside-in recording.

Another object of my present invention is to provide a novel advance ball attachment for phonographic recorders employing recording styluses, which attachment is arragned to dispose the advance ball on either side of the recording 2 stylus to thereby render such recorders suitable for either outside-in or inside-out recording on disc records.

Still another object of my invention is to provide an advance ball attachment as aforesaid which can be applied quite readily to existing recorder heads.

A further object of my present invention is to provide an improved advance ball recorder head as above set forth wherein the depth of cut of the recording styus in the record blank can be controlled regardless of whether the recorder is set for inside-out recording or `for outside-in recording.

Additional objects of my present invention are to provide an improved advance ball recorder head as above described which is of sturdy construction, which can be readily adjusted and set for operation even by one not highly skilled in the art, which is inexpensive in cost and readily lends itself to quantity production, and -Wlhich is extremely elcient in u-se.

The foregoing and other objects of my invention I accomplish by providing on a recorder head employing `a recording stylus an adjustable Iholder for the advance ball consisting of a flat plate, preferably of resilient or spring material. The plate may be attached to the under side of the recorder head with a pair of screws which extend through slots in the plate. These slots Iare arranged to permit transverse movement 0f the iplate relative to athe recording stylus so that an advance ball carried thereby may be located'on either side of the stylus. corder head may be set for either outside-in or inside-out recording, as desired. The resilient plate may be given an initial set to bias it against a vertical adjusting screw by means of which the advance lbali may be given vertical adjustment, or :adjustment in a direction parallel to the axis of the recording stylus for the purpose of regulating the Adepth of cut -of the stylus. The plate may be arranged in such relation to the vertical adjusting screw that it acts as a cantilever beam yclamped at one end by the screws extending through the aforementioned slots therein and freely suspended at its opposite end ywith which the vertical adjusting screw is in engagement.

'Ilhe novel features that I consider characteristie of my invention are set `forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, as Well as additional objects and advantages thereof, will best be understood from the following description of one em- In this Way, the rebodiment thereof, when read in connection with the accompanying drawing, in which Figure 1 is a sectional view of a recorder head taken along the line I-I of Fig. 2, and showing my improved advance ball attachment applied thereto,

Figure 2 is a sectional view taken on the line II-II of Fig. 1,

Figure 3 is a front elevation of the recorder head,

Figure 4 is a bottom plan View thereof showing the advance ball positioned for outside-in recording, and

Figure 5 is a View similar to Fig. 4 but showing the advance ball positioned for inside-out recording.

Referring more particularly to the drawing. wherein similar reference characters designate corresponding parts throughout, there is shown a. recorder head I having a cover 3 in which are enclosed the operative parts for driving a recording stylus 5 at the frequency of the signals to be recorded. The recorder may be of any suitable or approved form and, merely by way of illustration, is shown as being of the magnetic type.

The particular recorder head illustrated includes a magnet 'I which supplies flux to a pairof pole pieces 9 having an air gap I I therebetween and provided with a space for the reception of a coil I3. A socket or other suitable clamping member I5 is provided with an armature I'I' which terminates in the air gap II A centering spring I9 attached to the socket I5 serves to restore the armature I1 to centered position in the air gap II and may be adjusted to properly center the armature Il in the air gap I I by a plurality of adjusting screws 2|. The recording stylus 5 is held in the socket I5 by a set screw 23.

The construction thus far described is more or less conventional and therefore no further description thereof is believed to be necessary. Sui'ice it to say merely that signal voltages applied to the coil I3 will produce a flux which will either aid or oppose the iiux in the air gap II and hence cause the armature II to vibrate in correspondence with the applied signals. This, in turn, effects similar vibration of the stylus 5 and causes it to cut a groove in a record blank (not shown) which it engages.

Mounted on the bottom of the recorder head I is a plate provided with a pair of longitudinal slots 2'! through which extend a pair of screws 29 for adjustably securing the plate 25 to the bottom of the recorder head I. The plate 25 is preferably of resilient material and may be provided with a transverse slot 3| which aids in forming a hinge along approximately the dash lines 33 for a purpose to be presently set forth. Preferably, although not necessarily, the plate 25 may be provided with a downwardly extending flange 35 for stiffening the portion of the plate 25 between the hinge portion 33 and the freely suspended, right-hand end thereof, as viewed in Figs. 2, 4 and 5.

Between its hinge portion 33, 33 and its freely suspended end, the plate 25 is provided with a socket or clamping member 31 in which an advance ball 39 is firmly clamped by means of a screw 4I or the like. The clamping member 3l may be secured to the plate 25 in any suitable manner, as by rivets, spot welding, or the like 43. A vertically extending adjusting screw passes through the recorder head and engages the upper portion of the plate 25 adjacent the freely suspended end thereof, as best seen in Fig. 2. To

insure constant engagement of the plate 25 with the screw 45, the plate 25 may be given an initial set or bias so that, when it is clamped in place by the screws 29, the freely suspended end thereof will bear against the lower end of the screw 45.

It will be apparent from the foregoing description that, merely by loosening the screws 29 and shifting the plate 25 transversely of the recorder head I in directions transverse to the axis of the stylus 5, as indicated by the arrow A in Fig. 4 and the arrow B in Fig. 5, the advance ball 39 may be located or disposed either on the right or on the left of the stylus 5, as viewed in Fig. 2. When the plate 4 is moved in the direction of the arrow A and is clamped by the screws 29 in the position shown in Fig. 4, the recorder is set for outside-in recording on a disc record blank. On the other hand, by merely loosening the screws 29, shifting the plate '25 in the direction of the arrow B to the position shown in 5, and then tightening the screws 29 again, the advance ball 39 will be located on the opposite side of the stylus 5, thereby rendering the recorder suitable for ins-ide-out recording. As illustrated in the drawing, the advance ball is so located with respect to the stylus 5 that the latter must first be removed before the plate 25 can be shifted from one position to the other. However, it is apparent that the advance ball 39 may be so located with respect to the stylus that it will clear the stylus when the plate 25 is shifted from one p0- s-ition to the other, in which case it will not be necessary to iirst remove the stylus 5.

As will be seen from Figs. l, 2 and 3, the stylus 5 has its tip extending somewhat below the lower extremity of the advance ball. During operation of the recorder head, the advance ball rides on the surface of the record blank in advance of the stylus 5 in the direction of movement of the head over the record while the stylus 5 penetrates into the record, and the dilierence in height between the tips of the stylus 5 and the advance ball 39 determines the depth of cut or" the recording stylus. By merely manipulating the adjusting screw 45 in one direction or the other, the plate 25 can be caused to bend slightly along the hinge 33, 33 to thereby adjust the advance ball 39 vertically, or in a direction substantially parallel to the axis of the stylus 5. In this way, the depth of cut of the stylus can be readily set regardless of whether the recorder is conditioned for inside-out recording or for outside-in recording. However, once the depth of cut of the stylus 5 has been set by the screw 45, shifting the plate 25 to either one or the other of the two positions shown in Figs. 4 and 5 will not appreciably alter this depth.

From the foregoing description, it will be apparent to those skilled in the art that I have provided an advance ball attachment which can be applied to existing recorder heads, if desired, and which can be adjusted easily for either inside-out or outside-in recording by locating the advance ball on either side of the recording stylus. Although I have shown and described but one embodiment of my invention, it will undoubtedly be apparent that many other modifications, as well as changes in the one described, are possible within the scope of my present invention. I therefore desire that this invention shall not be limited except insofar as is made necessary by the prior art and by the spirit of the appended claims.

I claim as my invention:

1. In a signal recording device, the combination of a recording head, a stylus vibratively supported thereby for cooperation with a record, means associated with said stylus for imparting thereto vibrations to be recorded, an advance ball mounted on said recording head associated with said stylus for contact with the surface of the record whereby to determine the depth to which said stylus will penetrate the record, means adjustably mounting said advance ball for movement thereof in a plane normal to said stylus to one or another of two positions on opposite sides of said stylus and laterally with respect to the tracking movement of said stylus without altering a present stylus penetration depth, and adjustable means associated with said last named means for moving said advance ball in a plane substantially parallel to said stylus whereby to alter said penetration depth, said mounting means comprising an adjustable plate having a resilient hinge portion at one side thereof, said hinge portion including a slot along the hinge axis thereof, and a freely suspended end portion beyond said hinge portion.

2. In a signal recording device, the combination of a recording head, a stylus vibratively supported thereby for cooperation with a record, means associated with said stylus for imparting thereto vibrations to be recorded, an advance ball mounted on said recording head associated with said stylus for contact with the surface of the record whereby to determine the depth to which said stylus will penetrate the record, means adjustably mounting said advance ball for movement thereof in a plane normal to said stylus to one or another of two positions on opposite sides of said stylus and laterally with respect to the tracking movement of said stylus without altering a preset stylus penetration depth, and adjustable means associated with said last named means for moving said advance ball in a plane substantially parallel to said stylus whereby to alter said penetration depth, said mounting means comprising an adjustable plate having a resilient hinge portion at one side thereof, said hinge portion including a slot along the hinge axis thereof, and a freely suspended end portion beyond said hinge portion, and further characterized in that said adjustable means contacts said mounting means adjacent its freely suspended end whereby said stylus and said ad- Vance ball will be located in planes lying between said hinge portion and said adjustable means.

3. In a signal recording device, the combination of a recording head, a stylus vibratively supported thereby for cooperation with a record, means associated with said stylus for imparting thereto vibrations to be recorded, an advance ball mounted on said recording head associated with said stylus for contact with the surface of the record whereby to determine the depth to which said stylus will penetrate the record, means adjustably mounting said advance ball for movement thereof in a plane normal to said stylus to one or other of two positions on opposite sides of said stylus and laterally with respect to the tracking movement of said stylus without altering a preset stylus penetration depth, and adjustable means associated with said last named means for moving said advance ball in a plane substantially parallel to said stylus whereby to alter said penetration depth, said mounting means comprising an adjustable plate having av resilient hinge portion at one side thereof, said hinge portion including a slot along the hinge axis thereof, and a freely suspended end portion beyond said hinge portion, further characterized in that said adjustable means contacts said mounting means adjacent its freely suspended end whereby said stylus and said advance ball will be located in planes lying between said hinge portion and said adjustable means, and additionally characterized in that said mounting means is provided with a flange along one edge of said freely suspended end portion extending from said hinge portion to said freely suspended end.

HENRY E. ROYS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,046,414 Edison Dec. 3, 1912 1,126,428 Edison Jan. 26, 1915 1,874,101 Head Aug. 30, 1932 2,254,412 Badmaieif Sept. 2, 1941 2,318,308 Harris May 4, 1943 

